From 1e9704dca9a861ffb7b2d3978e1390bea7af7ef0 Mon Sep 17 00:00:00 2001
From: neoraider <devnull@localhost>
Date: Wed, 26 Sep 2007 19:28:04 +0000
Subject: zoomedit: ?berschlagene Polygone werden jetzt korrekt gerendert

---
 Triangle.cpp | 56 +++++++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 45 insertions(+), 11 deletions(-)

(limited to 'Triangle.cpp')

diff --git a/Triangle.cpp b/Triangle.cpp
index e367629..30bceb7 100644
--- a/Triangle.cpp
+++ b/Triangle.cpp
@@ -1,36 +1,70 @@
 #include "Triangle.h"
+#include "Line.h"
 #include <math.h>
+#include <stdio.h>
 
 
 Triangle::Direction Triangle::getDirection() const {
-  double c = (va.getX()-vb.getX())*(vc.getY()-vb.getY()) - (vc.getX()-vb.getX())*(va.getY()-vb.getY());
+  float c = (va.getX()-vb.getX())*(vc.getY()-vb.getY()) - (vc.getX()-vb.getX())*(va.getY()-vb.getY());
   
   return (c < 0) ? CW : (c > 0) ? CCW : Unknown;
 }
 
-double Triangle::area() const {
-  double a = vb.distanceSq(vc);
-  double b = vc.distanceSq(va);
-  double c = va.distanceSq(vb);
+float Triangle::area() const {
+  float a = vb.distanceSq(vc);
+  float b = vc.distanceSq(va);
+  float c = va.distanceSq(vb);
   
   return sqrt((a+b+c)*a+b+c - 2*(a*a+b*b+c*c))/4;
 }
 
-double Triangle::perimeter() const {
+float Triangle::perimeter() const {
   return va.distance(vb) + vb.distance(vc) + vc.distance(va);
 }
 
 bool Triangle::contains(const Vertex &v) const {
-  double a = (v.getX()-vb.getX())*(vc.getY()-vb.getY()) - (vc.getX()-vb.getX())*(v.getY()-vb.getY());
-  double b = (v.getX()-vc.getX())*(va.getY()-vc.getY()) - (va.getX()-vc.getX())*(v.getY()-vc.getY());
-  double c = (v.getX()-va.getX())*(vb.getY()-va.getY()) - (vb.getX()-va.getX())*(v.getY()-va.getY());
+  float a = (v.getX()-vb.getX())*(vc.getY()-vb.getY()) - (vc.getX()-vb.getX())*(v.getY()-vb.getY());
+  float b = (v.getX()-vc.getX())*(va.getY()-vc.getY()) - (va.getX()-vc.getX())*(v.getY()-vc.getY());
+  float c = (v.getX()-va.getX())*(vb.getY()-va.getY()) - (vb.getX()-va.getX())*(v.getY()-va.getY());
   
   switch(getDirection()) {
     case CW:
-      return ((a < 0) && (b < 0) && (c < 0));
+      return ((a < 1E-6) && (b < 1E-6) && (c < 1E-6));
     case CCW:
-      return ((a > 0) && (b > 0) && (c > 0));
+      return ((a > -1E-6) && (b > -1E-6) && (c > -1E-6));
   }
   
   return false;
 }
+
+bool Triangle::onEdge(const Vertex &v) const {
+  return (Line(va, vb).contains(v) || Line(vb, vc).contains(v) || Line(vc, va).contains(v));
+}
+
+int Triangle::intersectionCount(const Line &l) const {
+  int ret = 0;
+  Vertex v1, v2, v3;
+  
+  printf("Testing line: (%f %f) (%f %f)\n", l.getVertex1().getX(), l.getVertex1().getY(), l.getVertex2().getX(), l.getVertex2().getY());
+  if(Line(va, vb).intersects(l, &v1) == INTERSECTION_SEGMENT_SEGMENT) {
+    printf("Intersection: (%f %f)\n", v1.getX(), v1.getY());
+    ret++;
+  }
+  
+  if(Line(vb, vc).intersects(l, &v2) == INTERSECTION_SEGMENT_SEGMENT) {
+    printf("Intersection: (%f %f)\n", v2.getX(), v2.getY());
+    if(v2.distanceSq(v1) >= 1E-6)
+      ret++;
+  }
+  
+  if(Line(vc, va).intersects(l, &v3) == INTERSECTION_SEGMENT_SEGMENT) {
+    printf("Intersection: (%f %f)\n", v3.getX(), v3.getY());
+    if(v3.distanceSq(v1) >= 1E-6 && v3.distanceSq(v2) >= 1E-6)
+      ret++;
+  }
+  
+  printf("Found %i intersections.\n", ret);
+  
+  
+  return ret;
+}
-- 
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